Display apparatus

ABSTRACT

A multiplicity of modules is arranged to display a message, each module displaying one selected character that forms part of the message. Each module includes a strip of flexible material on which the characters that can be displayed are arranged in a series. The strip is wound from one spool to another under the power of a motor causing the characters to move successively through a viewing area. A strip-position-indicator presents a value of electrical resistance that corresponds, according to a predetermined code, to the position of the strip. If the resistance presented by the strip-position-indicator does not correspond to the character called for by a control means, a motor actuator causes the strip to be wound in the appropriate direction until that character is reached.

United States Patent Hodge, Jr. et al.

[54] DISPLAY APPARATUS [72] Inventors: Thomas Hodge, Jr., Watchung; Peter R. Bradie, Montvale, both of NJ.

[73] Assignee: EPC & G, lnc., Plainfield, NJ. by

said Hodge [22] Filed: March 12, 1971 [21] Appl.No.: 123,791

[52] US. Cl. ..340/3l7, 340/324 R, 340/154 [51] Int. Cl. ..G08b 23/00 [58] Field of Search ..340/317, 324 R, 325, 154; 235/61.12 C

[56] References Cited UNlTED STATES PATENTS 3,416,134 12/1968 Gertler et al ..340/324 R 3,046,542 7/1962 Hager ..340/324 R 3,418,635 12/1968 Sabulsky et al ..340/317 X [451 Oct. 17, 1972 Primary Examiner-John W. Caldlwell Assistant Examiner-Robert J. Mooney Attorney-Brumbaugh, Graves, Donohue & Raymond [57] ABSTRACT A multiplicity of modules is arranged to display a message, each module displaying one selected character that forms part of the message. Each module includes a strip of flexible material on which the characters that can be displayed are arranged in a series. The strip is wound from one spool to another under the power of a motor causing the characters to move successively through a viewing area. A stripposition-indicator presents a value of electrical resistance that corresponds, according to a predetermined code, to the position of the strip. If the resistance presented by the strip-position-indicator does not correspond to the character called for by a control means, a motor actuator causes the strip to be wound in the appropriate direction until that character is reached.

1 Claim, 7 Drawing Figures CONTROL MEANS MOTOR ACTUATOR MEANS l STRIP POSITION INDICATOR ,FROM MODULE minnow n ma FROM 1 CONTROL UNIT RESISTOR GROUP RESISTOR GROUP saw a or 4 v TO MOTOR FIGS INVENTORS'. THOMAS HODGE, JR. PETER R BRADIE their ATT R/VEYS 1 DISPLAY APPARATUS The present invention relates to a display apparatus, and more particularly to a new and highly effective display apparatus in which each of a plurality of modules displays a selected character that forms part of a message.

A number of types of display apparatus have been devised in which a plurality of characters, usually letters, numbers, and punctuation marks, can be selectively presented to display a desired message. These devices are used as theater marquees, to display the information at airports, and in many similar situations.

In a conventional theater marquee, for instance, opaque pieces of plastic or other material which have the-shape of the desired characters are manually affixed to an illuminated background. This is, of course, a time consuming process that requires accessibility to the display. In some locations, suchas at airports, this arrangement is notably disadvantageous because the information to be displayed is constantly changing, and the time taken to arrange the characters is too longin relation to the period during which they are displayed. Other types of devices have, therefore, been developed in which the characters to be displayed at each position are arranged on a movable strip of flexible material, and the selected characters can be moved into a display area to form part of the message. Each of the devices of this type which have been known previously have, however, embodied a. number of unfortunate disadvantages. Many require that the operator be able to see the display at the time that he selects the characters in order to stop the strip in the proper position. This is, of course, not possible in all situations. Other such devices include a series of indicia attached to the strip itself which are sensed electronically or photoelectrically to provide an indication of the character being displayed. Thus, the device can provide feedback to a remotely located control station. An arrangement of thistype is disclosed in U.S. Pat. No. 3,281,820 to Snider. Unfortunately, however, it requires a rather sophisticated sensing apparatus to detect the indicia as theymove rapidly past the sensing device. The problem of sensing the indicia is complicated by the fact that the indicia themselves must be capable of being carried by the strip and are, therefore, subjected to wear by friction and bending.

Many prior art devices, such as that disclosed in the Snider patent cited above, require a large amount of space in relation to the size and number of the characters displayed. Other known arrangements present difficulties in proper and effectively illuminating the background. Accordingly, there is a need for an improved display apparatus that overcomes many of the disadvantages inherent in the prior art devices.

SUMMARY OF THE INVENTION The present invention comprises an apparatus for displaying a plurality of selected characters that is relatively simple, reliable, can be easily and inexpensively manufactured, requires a minimum of space, and overcomes many other disadvantages associated with the prior art devices. It comprises a control means for selecting the characters to be displayed and a multiplicity of modules, each of which is adapted to display at least one character. Each module includes a strip of flexible material on which the characters that can be displayed by that module are arranged in a series. Two spools are arranged so that the strip can be wound from one to the other causing the characters to move successively through a viewing area. Each module also includes a motor for windingthe strip from one spool to the other and a strip-positionindicator means for presenting a value of electrical resistance that corresponds, according to a predetermined code, to the position of the strip. A motor-actuator means is electrically connected to the control means and the strip-position-indicator means for causing the motor to wind the strip in the appropriate direction until the resistance presented by the strip-position-indicator means corresponds to the character called for by the control means.

The control means and the strip-position-indicator means associated with each module include similar groups of resistors, one or more of which can be connectedin a circuit that includes the motor actuator means. The connection in the circuit of equivalent resistances in the control means and the strip-position-indicator means occurs when the character called for by the control means occupies the viewing. area.

The resistors of the strip-position-indicator means are selectively connected in the circuit by a rotatably mounted disc that is caused to turn in response to the movement of the strip. A plurality of concentric segmented rings are provided on the flat surface of the disc, one ring corresponding to each of the resistors. The segments of each ring are alternately conductive and nonconductive. A contact arm is associatedwith each ring to connect and disconnect the corresponding resistors depending upon whether the segment of the ring presented to the contacts is conductive.

The resistors of the control means are each associated with a set of normally closed electrical contacts that can be open by the insertion of a coded card whereby one or more resistors that present a combined resistance value corresponding to the character called for by the card are connected in the circuit that includes the motor-actuator means. The resistance presented by the control means is, in effect, compared to the resistance presented by the strip-position-indicator means, and the motor-actuator means produce a signal of the polarity necessary to cause the strip to be wound in the appropriate direction to bring the desired character into the viewing area.

The strip-position'indicator means may include an additional resistor and an associated additional segmented ring, whereby the resistances presented by the strip-position-indicator means and the control means are equal only when the character called for by the control means is properly aligned within the viewing area.

BRIEF DESCRIPTION OF THE DRAWINGS An understanding of additional aspects of the invention can be gained from a consideration of the following detailed description of a representative embodiment of the invention, taken in conjunction with the appended drawings wherein:

FIG. 1 is a pictorial, three-dimensional representation of a display apparatus constructed in accordance with the invention;

FIG. 2 is a top view of one of the modules that form the display apparatus of FIG. 1, the cover of the module having been removed;

FIG. 3 shows a partially broken-away view of part of a strip-position-indicator means included in the module shown in FIG. 2;

FIG. 4 is a schematic diagram of a push-pull amplifier that forms part of a motor-actuator means included in the module of FIG. 2;

FIG. 5 is a schematic diagram of the strip-position-indicator means partially shown in FIG. 3;

FIG. 6 is a chart showing a predetermined code according to which resistors can be connected to represent the characters to be displayed by the module shown in FIG. 2; and

FIG.7 shows a coded card adapted to be inserted in the control means of the apparatus shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a display apparatus in which a multiplicity of modules 10 are arranged in horizontal and vertical rows and held by a frame 12. Each of the modules is arranged to display one selected character that forms part of a message. In this embodiment, there are 21 modules that form three horizontal rows and seven vertical rows. The apparatus, as shown here, presents characters which form the words DISPLAY MESSAGE HERE. The modules 10 are constructed in horizontal groups of three, with single units added as needed to produce the desired pattern.

One of the modules 10 is shown in greater detail in FIG. 2. It includes a strip of flexible material 14 on which the characters that can be displayed are arranged in a series. The strip 14 can be wound between two spools l6 and 18 under the power of a reversible electric motor 20. As the strip 14 is wound from one spool 16, 18 to another the charactersmove successively through a viewing area 22 in which they are displayed as shown in FIG. 1 and illuminated by a lamp 24. Each lamp 24 is an elongated tube that passes through and illuminates a row of vertically aligned modules 10. Fluorescent lighting is preferred.

The strip 14 is held in tension by two constant tension springs 26, each of which is associated with one of the two spools 16 and 18. The number of turns of each spring 26 is at least equal to the number of rotations made by the associated spool 16 or 18 when the strip 14 is wound from one extreme position to the other. Thus, the strip 14 is able to move freely under the power of the motor to display any desired character but is always retained in sufficient tension to prevent it from developing slack that would detract from the appearance of the display or permit the strip 14 to skip and become disengaged from a pair of rotatable members 28 and 30 on which it is entrained. The rotatable members 28 and 30 are sprockets having teeth 31 that engage sprocket holes in the strip 14. One of the sprockets 28 is connected by a worm drive 32 to the motor 20.

A control means 34 is provided by which the operator of the apparatus can change the identity of the characters displayed from a remote location. The control means 34 is connected in a circuit with a motor-actuator means 36 and a strip-position-indicator means 38.

The indicator means 38 includes a rotatable disc 40, shown in a broken-away view in FIG. 3, which carries a plurality of six concentric, segmented rings 42 on its flat surface. The rings 42 include alternating conductive segments 44 and nonconductive segments 46. Each ring 42 is associated with a contact arm 48 and a resistor 50. The resistors 50 are shown schematically in FIG. 5. The disc 40 is connected to the sprocket 30 and is, thus, arranged to rotate in response to the movement of the strip 14. It makes one complete revolution in response to the movement of the strip 14 from one extreme position in which it is fully wound on one of the spools 16, 18 to the other extreme position in which it is fully wound on the other spool 16, 18. As the disc 40 rotates, the six contact arms 48 bear against different combinations of conductive and nonconductive segments 44 and 46 on the rings 42. This determines which of the six resistors 50 will be connected in the circuit including the motor-actuator means 36. For each character carried by the strip 14 there is a unique position of the disc 40, and thus a corresponding unique combination of resistors 50. The strip-position-indicator means 38, therefore, presents a unique value of electrical resistance that corresponds, according to a predetermined code, to the character displayed in the viewing area 22.

An example of a predetermined code in which each character is assigned a unique value of resistance is shown in chart form in FIG. 6. Each of these characters, starting with the letter A and ending with the number 9, are arranged on the strip 14 in the same order as they are arranged in the chart. The combined value of the resistors 50 which the rings 42 caused to be included in the circuit with the motor-actuator means 36 when that character is displayed in the viewing area 22 increases as the list of characters is descended. The resistors 50 to be included in the combination corresponding to each character are indicated by an X'on the chart. The resistance values of the resistors 50 may be selected so that the appropriate resistance is presented when the resistors are connected in either series or parallel as desired. The resistors should be selected so that their resistances are neither equal nor multiples of each other so that different combinations of resistors will not present equal values of resistances.

The strip-position-indicator means 38 includes an additional ring 52 which is similar to the rings 42 and is associated with an additional contact arm 54 and an additional resistor 55. The number of conductive segments on the ring 52 is equal to the number of characters carried by the strip 14. The purpose of this additional ring 52 is to cause the strip-position-indicator means 38 to present the resistance value corresponding to a particular character only when that character is properly aligned within the viewing area 22. When no character is properly aligned within the viewing area 22, the resistance presented by the strip-position-indicator means 38 will not correspond to that assigned to any of the characters because the additional resistor 55, for which there is no corresponding resistor in the control means 34, will be included in the combination. The additional ring 52 and the corresponding resistor 55 could be eliminated, but its presence is desirable to reduce or eliminate misalignment of the characters.

The control means 34 contains a group of six resistors 56 (shown in FIG. 5) similar to those included in the striplposition-indicator means 38. Each of the resistors 56 corresponds to one of the resistors 50. A set of separable electrical contacts 58 is associated with each of the six resistors 56. As noted above, the control means 34 does not include a seventh resistor corresponding to the additional resistor 54.

The operator of the display apparatus is provided with a deck of coded plastic cards, one card corresponding to each of the characters on the strip 14. FIG. 7 shows a card 60 which represents the letter W according to the code of FIG. 6. The card 60 can be conveniently inserted in a slot in the control panel of the control means 34, and the presence or absence of a notch opposite each of the six contacts 58 will either permit them to remain closed or force them open. In this case, the first and third sets of contacts 58, starting from the left, will be opened and the corresponding resistors 50 will be excluded from the combination.

When a card is inserted, the control means 34 presents to the motor-actuator means 36 a resistance value equal to that presented by the strip-position-indicator means 38 when the character called for by the inserted card occupies the viewing area 22. If the character called for by the control means 34 is not displayed in the viewing area 22, the value of resistance presented by the strip-position-indicator means 38 will not be equal to the value of the resistance presented by the control means 34. The motor-actuator means 36 produces a current in response to this difference in resistance values that causes an amplifier 74 to supply power to the electric motor 20.

The motor actuator means 36 incorporates a pushpull amplifier 62 that is shown schematically in FIG. 4. The amplifier 62 includes an n-p-n transistor 64 and a p-n-p transistor 66 connected by a line 68 which is in turn connected to the group of resistors 50 that form part of the strip-position-indicator means 38 and the group of resistors 56 that form part of the control means 34. If the resistance values presented by the indicator means 38 and the control means 34 are not equal, a bias potential is applied to the line 68. The polarity of this potential will depend upon which of the two resistance values presented by the control means 34 and the strip-position-indicator means 38 is the greater. If the polarity is such that the transistor 64 is forward biased, it will in turn forward bias the transistor 70, causing the motor to rotate in one direction. If the potential forward biases the transistor 66, it will forward bias transistor 72 causing the motor 20 to rotate in the opposite direction. The amplifier 62 is connected to another amplifier 74 which is inserted between the motor-actuator means 36 and the motor 20 to further increase the potentialapplied to the motor.

The motor-actuator means 36 further includes a delay means that prevents a signal from being transmitted to the motor 20 for a period of approximately 30 seconds to two minutes after a change in resistance presented by the control means 34 occurs. This prevents the motor 20 from being actuated in response to erroneous signals caused by transient conditions or the partial insertion of a coded card.

It is important that the resistance valuesassociated with he characters on the band 14 are not arranged in a random order. Instead, the resistance presented by the strip-position-indicator means 38 continuously increases or decreases as the strip 14 moves in a given direction. Therefore, the motor 20 always turns in the appropriate direction to bring the desired character into the viewing area 22. As the appropriate character is reached, the difference in resistances decreases and the bias potential applied to the amplifier 62 decreases accordingly. This causes the motor 20 to slow down preventing the strip 14 from over shooting. If, however, the strip 14 were to move too far, it would cause the potential applied to the motor 20 to be reversed, and the motor 20 would slowly wind back to the proper position.

The apparatus described above possesses numerous advantages as compared to prior art devices. It is relatively simple and compact, and it can be controlled from a remote location by an unskilled operator. The provisions for positioning the strip 14 to display the desired character are reliable and highly effective.

It will be obvious to those skilled in the art that the above-described embodiment is meant to be merely exemplary and that it is susceptible of modification and variation without departing from the spirit and scope of the invention. Therefore, the invention is not deemed to be limited except as defined by the appended claims.

I claim:

1. An apparatus for selectively displaying a group of characters that form a message comprising a control means for selecting the characters to be displayed and a multiplicity of modules each of which is adapted to dis play at least one character, each module including a strip of flexible material on which the characters that can be displayed by that module are arranged in a series, two spools arranged so that the strip can be wound from one spool to the other causing the characters to move successively through a viewing area, a motor for winding the strip from one spool to the other, a stripposition-indicator means for presenting a value of electrical resistance that corresponds according to a predetermined code to the position of the strip, and a motor-actuator means electrically connected to the control means and the strip-position-indicator means for causing the motor to wind the strip in the ap-' propriate direction until the resistance presented by the strip-position-indicator means corresponds to the character called for by the control means, wherein the strip-position-indicator means comprises a rotatably mounted disc having a plurality of concentric seg mented rings on the flat surface thereof one ring corresponding to each of the resistors and at least one segment of each ring being electrically conductive, a group of resistors each having a different resistance, and a contact arm that bears against each ring to connect and disconnect the corresponding resistor depending on whether the portion of the ring presented to the contact arm is conductive; wherein the control means includes a group of resistors each of which corresponds to and has a value of resistance substantially equal to one of the resistors of the strip-position-indicator means, whereby corresponding resistors in the control means and the strip-position-indicator means are connected to the motor-actuator means when the character that occupies the viewing area is the same character called for by the control means; and wherein the strip-position-indicator means and a control means are equal only when the character called for by the control means is properly aligned within the viewing area.

* l l l 

1. An apparatus for selectively displaying a group of characters that form a message comprising a control means for selecting the characters to be displayed and a multiplicity of modules each of which is adapted to display at least one character, each module including a strip of flexible material on which the characters that can be displayed by that module are arranged in a series, two spools arranged so that the strip can be wound from one spool to the other causing the characters to move successively through a viewing area, a motor for winding the strip from one spool to the otheR, a strip-position-indicator means for presenting a value of electrical resistance that corresponds according to a predetermined code to the position of the strip, and a motoractuator means electrically connected to the control means and the strip-position-indicator means for causing the motor to wind the strip in the appropriate direction until the resistance presented by the strip-position-indicator means corresponds to the character called for by the control means, wherein the stripposition-indicator means comprises a rotatably mounted disc having a plurality of concentric segmented rings on the flat surface thereof one ring corresponding to each of the resistors and at least one segment of each ring being electrically conductive, a group of resistors each having a different resistance, and a contact arm that bears against each ring to connect and disconnect the corresponding resistor depending on whether the portion of the ring presented to the contact arm is conductive; wherein the control means includes a group of resistors each of which corresponds to and has a value of resistance substantially equal to one of the resistors of the strip-position-indicator means, whereby corresponding resistors in the control means and the strip-position-indicator means are connected to the motor-actuator means when the character that occupies the viewing area is the same character called for by the control means; and wherein the strip-position-indicator means includes an additional resistor and an additional ring carried by the rotatable disc, the additional ring including a conductive segment corresponding to each of the characters on the strip, whereby the resistance values presented by the strip-positionindicator means and the control means are equal only when the character called for by the control means is properly aligned within the viewing area. 